The multiband behavior of the Sierpinski patch antenna is described, and a new technique to improve the multiband behavior from the point of view of the radiation patterns is introduced. The technique suppresses the effects of the high order modes and a patch antenna with similar radiation patterns can be designed. Once the high order mode has been suppressed for the second band, the next step is to try eliminate it for the third and fourth band breaking the appropriate junctions.
Borja, C., Romeu, J. Multiband Sierpinskl fractal patch antenna. A: IEEE International Symposium on Antennas and Propagation. "IEEE Antennas and propagation international symposium". salt lake city: Institute of Electrical and Electronics Engineers (IEEE), 2000, p. 2-3.